Mango fruit quality improvements in response to water stress

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Horticultural Science (Prague), 48, 2021 (1): 1–11 Original Paper

https://doi.org/10.17221/45/2020-HORTSCI

The mango (Mangifera indica L.), is a large ever-green tree, and belongs to the Anacardiaceae family, which originated in the foothills of the Himalayas in southern Asia bordering the Bay of Bengal (Bom-pard 2009). The varieties that evolved in the tropi-cal areas have seeds with several genetically identical embryos (poly-embryonic) and oppositely, mangos that developed in the subtropical areas of the Indian sub-continent are mono-embryonic (Mukherjee,

Litz 2009). Nowadays, it is cultivated from the tropics and subtropics up to the northern latitudes of 35–37° in the south of Spain (Galán, Lu 2018).

The quality performance of mango fruits depends on external and internal quality parameters. That is, the internal quality attributes comprise a uniform and intense flesh colour, and contain adequate acid-ity, vitamins, and a pleasant sweetness (Kader 2002). Mangos contain both provitamin A carotenoids,

Mango fruit quality improvements in response to water stress: implications for adaptation under environmental constraints

Víctor Hugo Durán Zuazo1*, Dionisio Franco Tarifa2, Belén Cárceles Rodríguez1, Baltasar Gálvez Ruiz1, Pedro Cermeño Sacristán3, Simón Cuadros Tavira4, Iván Francisco García-Tejero3

1IFAPA Centro “Camino de Purchil”, Granada, Spain2Auntamiento de Almuñécar, Almuñécar, Spain3IFAPA Centro “Las Torres”, Sevilla, Spain4Departemento de Ingeniería Forestal, Universidad de Córdoba, Córdoba, Spain*Corresponding author: [email protected]

Citation: Durán Zuazo V.H., Franco T.D., Cárceles R.B., Gálvez R.B., Cermeño S.P., Cuadros T.S., García T.I.F. (2021): Mango fruit quality improvements in response to water stress: implications for adaptation under environmental con-straints. Hort. Sci. (Prague), 48: 1–11.

Abstract: Mediterranean farming is facing increasing periods of water shortage and, in the coming decades, the water reduction is expected to exert the most adverse impact upon growth and productivity. This study was performed to assess the response of the physico-biochemical quality parameters of mango fruits to different doses of irrigation in a Mediterranean subtropical area in Spain. During two-monitoring seasons, trees were subjected to deficit-irrigation strategies receiving 33, 50, and 75% of a crop evapotranspiration (ETC), and a control at 100% ETC. According to the findings and respect to control, the yield was reduced in 8, 11, and 20% for the water-stressed trees at 75, 50, and 33% ETC, respectively, producing smaller fruits in line with the amount of applied irrigation. However, the water-stressed fruits significantly enhanced their quality, in particular at 33% ETC, with regards to the content of the health-promoting phytochemicals (total soluble solids, vitamin C, and β-carotenoids). Thus, sustainable water management without a detrimental effect on the yield could be possible, and farmers should be encouraged to adapt to the environmental constraints, producing improved quality fruits.

Keywords: mango fruit; physico-biochemical fruit parameters; sustainable water-savings; subtropical farming; water shortage

Partly funded by the research Project: “Innovations for sustainability, productivity, and improvement of subtropical crops (mango and cherimoya)” (PP.AVA.AVA2019.38) and co-financed by the European Regional Development Fund (ERDF), Internal call for Research Projects and Technological Innovation for the period 2019–2022.

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Original Paper Horticultural Science (Prague), 48, 2021 (1): 1–11


such as α-carotene, β-carotene, and γ-carotene; and oxygenated carotenoids (xanthophylls), such as β-cryptoxanthin, violaxanthin, auroxanthin, ne-oxanthin, among others (Palafox et al. 2012).

In the European Mediterranean basin, concretely in Spain, and according to ESYRCE (2018), the area devoted to subtropical crops is approximately 4.3% of the total surface with fruits trees, and 2.2% of the total production. The subtropical fruits are mainly established in the coast of Malaga and Granada, and in the Canary Islands. In this sense, in 2018, there were 4 276 ha of irrigated mangos in Spain of which 3 994 ha were located in Andalusia. On the other hand, the cultivars most used by farmers are the Florida cultivars, such as Osteen, Keitt, Tom-my Atkins, among others, also being the most used by the main mango producing countries (Durán et al. 2003; Durán, Franco 2006; Gentile et al. 2019).

The expansion and intensification of land use in ag-riculture have promoted an increase in the water de-mand, especially in the Mediterranean area (Durán et al. 2013; García, Durán 2018), as well as in other regions (Ali et al. 2017). In this sense, a water short-age is one of the most important environmental con-straints on fruit woody crops and limits the produc-tivity, and, consequently, the economic development. Despite the relative tolerance of mangos to drought, the needed production can only be achieved by irri-gation (Durán et al. 2003; Galán, Lu 2018).

All these challenges need a persistent effort to im-prove the agronomical practices and response to the environmental constraints. Thus, in this study, we

monitored the alterations in the mango (cv. Osteen) fruit quality parameters due to water stress by sub-jecting the mangos to different deficit irrigation strategies under a subtropical Mediterranean cli-mate in south-east Spain.

MATERIAL AND METHODS

Experimental site. The experiment was execut-ed over two-growing seasons (2018–2019) in Al-muñécar, the Granada coast (SE Spain, 36°48′00”N, 3°38′0”W). According to Elias and Ruiz (1977), the local temperatures are subtropical to semi-hot within the Mediterranean subtropical cli-matic category, and has an average annual rainfall of 449.0 mm. The shallow soils formed from weath-ered slates, vary in depth, and some are rocky, pro-viding generally very good drainage, and are classi-fied as a typical xerorthent, with 684, 235, and 81 g/kg of sand, silt and clay.

The experimental mango plantation is located on terraces that are commonly found in the area (Fig-ure 1A). Each platform had a single row of 16-year-old mango trees (Mangifera indica L. cv. ‘Osteen’ grafted onto ‘Gomera-1’) (Figure 1B), healthy and uniform in size, and spaced 3 m apart. Three deficit-irrigation strategies that received 33%, 50%, and 75% of the ETC, compared with a control of fully irrigated trees at 100% ETC, were studied. To estimate the ir-rigation requirements, the reference evapotranspira-tion (ET0) was calculated according to the Penman-Monteith methodology, using local crop coefficients

Figure 1. Orchard terraces with a mango plantation (A) and cv. ‘Osteen’ mango trees (B)

(A) (B)

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KC previously defined in the studied area (Rodríguez et al. 2011). The experimental design was a completely randomised block design with three replications per treatment. Each replication had eleven trees, the five central trees of the rows were used for measurements of the fruit yield and the others served as border trees.

Physical fruit quality measurements. n the stud-ied trees, five fruits were selected for the growth measurements (polar and equatorial diameters), using a digital calliper throughout the production cycle (Figure 2). The mango fruits were harvest-ed at the pre-climacteric hard-green stage, thirty healthy fruits free from diseases and insect infes-tation were selected, determining their weight and size. The fruits were stored at 12ºC and 85–90% rela-tive humidity until they reached the proper matu-rity level (~ 8–10 days) (Salunkhe 1984). The man-go fruits were peeled and the pulp, seed, and peel separated, and each fraction was weighed. Moreo-ver, the texture parameter was measured through a fruit penetrometer (PCE-PTR 200) with crossheads of 6 and 8 mm. Ten fruits were used to determine the colour [L*, a*, b* and hue angle (h°)]. The peel colour and pulp colour of the fruits were measured using a MINOLTA CM-700d spectrophotometer (Minolta CO. Tokyo, Japan) and according to the procedure by McGuire (1992).

Biochemical fruit quality measurements. The total soluble solids (TSS) were examined by taking pulp samples previously homogenised in a blender (a few drops) with a refractometer as Brix degrees (AOAC 1984). The titratable acidity (TA) was mea-sured in the pulp by titrating against NaOH. The fruit samples from each treatment were homogenised for the pH measurements with a digital pH-meter.

The vitamin C (ascorbic acid) content was mea-sured following the procedure of redox titration us-ing an iodine solution (UC 2019). The profile of the carotenoids was determined by high-performance liquid chromatography (HPLC), and extracted with acetone and saponification with KOH (10% in meth-anol). The extract was evaporated (Fisatom Model 801) (T < 25°C) and stored (–18°C) for quantifica-tion by HPLC (Mercadante, Rodríguez 1998). Simi-larly, the anthocyanins were determined by taking the fruit sample previously homogenised in an Ul-tra- Turrax with acidified methanol (HCl 1%) and then quantified by HPLC (Zanatta et al. 2005).

An analysis of variance (ANOVA) using a statisti-cal analysis package (Statgraphics Centurion XVIII) was performed in order to ascertain the differenc-es in the fruit quality parameters. The differences were tested using the least significant difference test (LSD) at a P < 0.05 level. In addition, the linear functions were adjusted between the fruit growth and the days of the year.

RESULTS AND DISCUSSION

Fruit growth and physical parameters. Figure 3 shows the growth of the fruits in response to the irrigation strategies applied during the monitor-ing period. In general, the fruit growth was rela-tively slow at the early stages, was faster at the rapidly expanding stage, and slowed down at the maturity stage. The water stress repercussions on the fruit growth were explicitly perceptible with the most severe irrigation of 33% ETC in relation to the control (100% ETC), being remarkable in the second season. For the study period, in average

Figure 2. Field measurements of the polar (A) and equatorial (B) diameter in the mango fruits

(A) (B)

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0

50

100

150

200

180 199 206 213 228 234 241 258

Polar Equatorial(mm)

100% ETC

A

020406080

100120140160

180 199 206 213 228 234 241 258

Polar Equatorial D

33% ETC

(mm)

020406080

100120140160

180 199 206 213 228 234 241 258

Polar Equatorial C

50% ETC

(mm)

terms, the growth rate for the polar and equato-rial diameters at 33% ETC with respect to control were reduced by 9 and 10%, 2 and 5% with respect to the 50% ETC, and 1 and 4% with respect to the 75% ETC, respectively. As it is well-known, the pro-cess of cell enlargement and division need a water supply during the fruit growth period, and the lack of water at 33% ETC inhibited the fruit growth and development. A week before the harvest, the av-erage polar and equatorial fruit diameters in the control trees were 140.5 and 98.5 mm, and were 127.7 and 88.4 mm for the most severe deficit ir-rigation, respectively. In general, the size of the fruits at 50% ETC was reasonably less affected, but had a significant water savings. This fact was clearly corroborated with the rate of growth of the man-go fruit in the present study according to amount of applied irrigation water. Moreover, as was stated by Lawlor and Cornic (2002), the water stress re-duces the fruit growth by slowing down the rate of cell division and expansion due to the loss of tur-gor and the increased abscisic acid synthesis.

Table 1 presents the functions for the fruit growth and the monitoring day of the year during the study period. In general terms, the mango fruit shape

was semi elliptic and its growth fits an exponential curve (single sigmoid). The models describe the pro-cesses involved in the fruit growth and their rela-tionship to the external conditions. For all the treat-ments, the fruit growth was highly correlated with the monitoring days, especially those related to the equatorial diameter. In addition, there was a de-creasing trend in the relationship from the non-stressed (100% ETC) to the most water-stressed trees (33% ETC). Although the coefficients of correlation for the pooled data were less than for each treatment, these data described that the model is acceptable.

Table 2 displays the impact of the irrigation strate-gies on the average size and weight of the harvested fruits during the study. Moreover, the average fruit yield for the trees under the 75% ETC, 50% ETC, and 33% ETC was of 38.8, 37.6, and 33.9 kg/tree, re-spectively, and the average fruit yield of the control trees (100% ETC) was 42.2 kg/tree. The reduction in fruit productivity was clearly evident by the effect of the water irrigation amounts. On the other hand, the fruits from the control trees had the highest av-erage weight (659.2 g), the difference with respect to the severe deficit irrigation (33% ETC) being statis-tically significant (P < 0.05), while the rest of the fruits

Figure 3. Average mango fruit growth rate in the polar and equatorial diameters in response to the deficit-irrigation in the control trees at 100% ETC (A), at 75% ETC (B), at 50% ETC (C), and 33% ETC (D)

DOY – day of the year; the vertical bars are the standard deviation

(A) (B)

(C) (D)

DOY

DOY

DOY

DOY

0

50

100

150

200

180 199 206 213 228 234 241 258

Polar Equatorial(mm)

100% ETC

A

(mm

)

020406080

100120140160

180 199 206 213 228 234 241 258

Polar Equatorial B

75% ETC

(mm)

(mm

)

(mm

)

(mm

)

(B)

5



did not differ statistically from each other. This fact is agreed with by Madigu et al. (2009), who reported a decrease in the weight of water-stressed fruits.

The fruit weight loss for the control fruits (100% ETC) with respect to the 75% ETC, 50% ETC, and 33% ETC was 2, 3, and 25%, respectively. The water stress in the early stage of the fruit de-velopment process provoked the fruit to drop (data not shown), which reduced the number of fruits in the most water-stressed treatments at 33% ETC. The peel and pulp fruit fractions were not affected by the irrigation; however, under deficit conditions, the seed was significantly reduced, showing a simi-lar trend to that was found for the weight. The high-est pulp:seed ratio was determined for the 33% ETC (12.8), and the lowest for the control fruits (10.7), and the remaining treatments had an intermediate value.

The textural firmness was not affected by the wa-ter stress, although an increasing trend was fixed at 33% ETC (Table 2). This is in contrast to the results reported by Abdel-Razik et al. (2012), who showed that a reduction in irrigation water (70% ETC) in-creased the fruit firmness compared with the fully irrigated trees (100% ETC). Additionally, Madigu et al. (2009) concluded that the fruit firmness of well irrigated (2.0 ± 0.6 kg/m2) and water-stressed (2.5 ± 0.9 kg/m2) trees was significantly different with the latter being firmer, which corroborated the findings of our study. The shape index obtained from the ratio between the polar and equatorial di-

ameters indicated a decreasing trend with the fruit development, and a more pronounced flattened shape prevailing among the control, 75%, and 50% ETC treatments in contrast with the more severe treatment at 33% ETC (Figure 4).

Table 3 shows the effects of the irrigation on the external and internal fruit colour attributes in response to the deficit irrigation. The changes in the pulp colour on the fruits were as follows: the pulp brightness L and hue values significantly in-creased from 64 and 77 in the non-stressed to 72 and 83 in the severe water-stressed trees, respectively, similarly the pulp chroma values increased from 28 (100% ETC) to 34 (33% ETC) (P < 0.05). For the peel colour, no significant changes were found in the peel brightness as well as for chroma values, in contrast with the peel hue values.

In general, the water stress encouraged the fruit ripening as did the increased peel and pulp col-oration. These findings were in accordance with to Spreer et al. (2007), who stated that the peel co-lour (degrees hue angle) in fruits from water-stressed trees (50% ETC) was greater than in the fruits from the fully irrigated trees, while the mesocarp colour did not differ in the fruit from the fully irrigated trees. On the contrary, the pulp colour changes were uniform, that is, the increase in the yellow-orange intensity of the mango cv. Osteen pulp can be as-sociated with an augmentation in the carotenoid content, as was pointed out by Ibarra et al. (2015).

Table 1. Relationships between the fruit growth and the day of the year

Irrigation strategyPolar diameter Equatorial diameter

equation r2 equation r2

100% ETC (Control) y = 71.23e0.0027x 0.890 y = 33.66e0.0042x 0.93475% ETC y = 73.05e0.0026x 0.849 y = 37.19e0.0037x 0.88750% ETC y = 87.45e0.0019x 0.873 y = 47.32e0.0028x 0.87033% ETC y = 80.83e0.0018x 0.868 y = 42.82e0.0029x 0.890Pooled data y = 77.88e0.0022x 0.649 y = 39.91e0.0034x 0.805

Table 2. Impact of the irrigation on the cv. ‘Osteen’ mango fruit size during the two-monitoring periods

Irrigation strategy Irrigation (m3/ha)

Diameter (mm)Weight(g) Firmness

(kg/m2)Fruit fraction (%)

polar equatorial pulp peel seed

100% ETC (Control) 5,451 140.8 ± 12.4a 95.9 ± 7.1a 659.8b 2.0 ± 0.6a 84.2 ± 1.1a 7.9 ± 0.8a 7.9 ± 0.7a

75% ETC 3,933 140.2 ± 12.5b 95.0 ± 7.6b 649.1b 2.1 ± 0.8a 84.2 ± 2.4a 8.5 ± 0.8a 7.3 ± 0.8ab

50% ETC 2,730 141.9 ± 9.5b 95.8 ± 5.9b 643.2b 1.8 ± 0.5a 84.9 ± 1.8a 8.0 ± 1.5a 7.1 ± 0.9ab

33% ETC 2,275 130.5 ± 14.2b 88.8 ± 6.5b 492.5a 2.5 ± 0.9a 84.7 ± 3.4a 8.7 ± 1.7a 6.6 ± 1.6b

Values with different letters within the same column are statistically different (P < 0.05; LSD); ± standard deviation

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y = –0.0016 x + 1.8433 r² = 0.831

1.42

1.44

1.46

1.48

1.50

1.52

1.54

1.56

1.58

150 170 190 210 230 250 270

D

33% ETC

(D)

y = –0.0014 x + 1.8164 r² = 0.808

1.44

1.46

1.48

1.50

1.52

1.54

1.56

1.58

150 170 190 210 230 250 270

C

50% ETC

(C)

y = –0.0017 x + 1.911 r² = 0.785

1.441.461.481.501.521.541.561.581.601.62

150 170 190 210 230 250 270

B

75% ETC

y = –0.0023 x + 2.021 r² = 0.910

1.40

1.45

1.50

1.55

1.60

1.65

150 170 190 210 230 250 270

A

100% ETC

In this sense, the peel colour development, as re-vealed by Wei et al. (2017), was highly affected by the fruit position on the tree and with a significant influ-ence from the irrigation practices.

Biochemical parameters. Table 4 displays the biochemical parameters determined throughout the study. The mango fruits differed significantly in the titratable acidity (TA), registering the low-est (0.17%) values for the 33% ETC in contrast with 0.27% for the 100% ETC. A significantly increasing trend was fixed in the total soluble solids (TSS),

pH, and TSS/TA ratio with the amount of applied irrigation water; being higher in all the water-stressed treatments, particularly with the 33% ETC. On the other hand, the lowest vitamin C content was found in the control fruits, having a 42, 34, and 8% increase in the fruits at the 33% ETC with respect to the 100% ETC, 75% ETC, and 50% ETC, respectively. This is in conformity with Nagle et al. (2010), who reported that abundant irrigation can reduce the TSS in the fruits due to the dilution ef-fect. Abdel-Razik et al. (2012) concluded that the

Figure 4. Shape index for the mango fruit during the study period in the control trees at at 100% ETC (A), at 75% ETC (B), at 50% ETC (C), and 33% ETC (D)

DOY – day of the year

Table 3. Effect of the irrigation on the colour attributes for the peel and pulp of the cv. ‘Osteen’ mango fruit

Irrigation strategy L* C* h*External peel-coloration

100% ETC (Control) 42 ± 2a 54 ± 4a 48 ± 11a

75% ETC 43 ± 2a 52 ± 2a 49 ± 15a

50% ETC 41 ± 3a 55 ± 3a 53 ± 13ab

33% ETC 44 ± 3a 57 ± 5a 54 ± 8b

Pulp-internal coloration100% ETC (Control) 64 ± 4a 28 ± 1a 77 ± 2a

75% ETC 65 ± 5a 28 ± 4a 78 ± 5a

50% ETC 70 ± 3b 31 ± 3ab 81 ± 2a

33% ETC 72 ± 5b 34 ± 6b 83 ± 4b

Values with different letters within the same column are statistically different (P < 0.05; LSD); values ± standard deviation

(A) (B)

Shap

e in

dex

DOY

Shap

e in

dex

Shap

e in

dex

Shap

e in

dex

DOY

DOY

DOY

7



TSS increased with a reduction in the irrigation water, as was found in the present study.

Besides, carbohydrate metabolism plays a sig-nificant role during the mango fruit development; according to Madigu et al. (2009), the fruits from rainfed or deficit-irrigated trees contained a higher starch content than the fruits from fully irrigated trees. The values for the TSS are generally higher than those revealed by Fernández et al. (2001) for cv. Osteen of 14%, and this may be due to the longer period of sunlight exposure, since the ex-perimental trees were cultivated on south-facing terraces. In this context, a positive relationship be-tween the light-exposure time and the TSS has been reported by Tombesi et al. (1993). As the TSS/TA ratio is considered a measure of the fruit quality, it is generally accepted that quality fruits have a high-er ratio. Palaniswamy et al. (1975), reported a ratio for high-quality mangos from 131.3 to 162.5, being, in our conditions, the highest TSS/TA ratios for the fruits subjected to the 33% ETC. According to our findings, the highest TSS/TA ratios were found for the cv. Osteen when the trees were subjected to most severe water-stressed treatments.

Mitra and Mitra (2001), for nineteen mango cul-tivars, reported a vitamin C content ranging from 21.66 to 125.40 mg per 100 g, being that such varia-tion could be attributed to the nature and extent of the genetic variability. Therefore, in our case, the alteration was a response to the applied water stress. Similarly, Ferreira et al. (2018) reported 31.9, 29.7, 29.7, 51.4 and 34.3 mg per 100 g for the Florida cultivars ‘Tommy Atkins’, ‘Haden’, ‘Kent’, ‘Palmer’, and ‘Keitt’, respectively. The differences in the values for the vitamin C may be associated with such fac-tors as the maturation stage of the fruit, the growing conditions and climate, among others.

Table 5 shows the water stress impact on the carot-enoid and anthocyanin contents in the mango fruits.

In this sense, the violaxanthin, β-carotene, and an-theraxanthin contents augmented by the effect of the deficit irrigation, particularly at 33% ETC, were in contrast to the neoxanthin and β-cryptoxanthin contents that showed an indefinable trend. Conse-quently, the water stress led to an increase in the main carotenoid contents in the fruits with respect to the fruits from the control trees. Studies regard-ing the impact of deficit irrigation on the carot-enoid contents in mango fruits are scarce. How-ever, there is a huge amount of literature reporting the great variability in the carotenoid contents, for example, Chen et al. (2004) reported almost sim-ilar values of 9.86, 6.4, and 1.88 μg/g for Taiwanese mango fruits with those found in the present experi-ment for β-carotene, violaxanthin and neoxanthin, respectively. On the other hand, the values obtained in the present study, in particular for the β-carotene in the pulp, were similar to those revealed in other studies. Rocha et al. (2007) reported from 6.61 (cv. ‘Palmer’) to 22.2 μg/g (cv. ‘Uba’), Godoy and Ro-dríguez (1989) reported on the cv. ‘Had’en (from 4.94 to 0.82 μg/g) and the cv. ‘Tommy Atkins’ (from 12.09 to 14.05 μg/g). However, the β-carotene con-tents found in this study are nearly similar to the values reported by the European carotenoid data-base for fruits (13.0 μg/g) (O’Neill et al. 2001).

Regarding the anthocyanin contents, concretely to methylcyanidin-glycoside, cyanidin-3- glyco-side, and other anthocyanins, they were not clearly altered by the water stress. However, Madigu et al. (2009) reported that the β-carotene content aug-mented with a gradual reduction in the anthocya-nins towards the fruit maturity, and the fruits from the non-irrigated trees had a higher anthocyanin content with respect to the fruits from the irrigated trees. Similarly, the results of the present experiment fixed an increasing trend in the anthocyanin con-tent in the mango fruits from the 100% ETC to the

Table 4. Biochemical parameters for the mango fruits during the two-monitoring periods

Irrigation strategy TSS (ºBrix)

TA (g acid /100 cm3) pH TSS/TA

ratioVitamin C

(mg /100 g)100% ETC (Control) 17.0 ± 2.3a 0.27 ± 0.09a 4.5 ± 0.19a 74.4 ± 21.7a 21.7 ± 5.3a

75% ETC 18.1 ± 1.4ab 0.21 ± 0.15ab 4.6 ± 0.37a 79.1 ± 25.2a 24.4 ± 8.0ab

50% ETC 18.5 ± 2.2ab 0.18 ± 0.08b 4.8 ± 0.23a 108.5 ± 27.6b 34.3 ± 4.9ab

33% ETC 18.9 ± 3.0b 0.17 ± 0.10b 5.6 ± 0.18b 126.9 ± 23.6b 37.2 ± 17.7c

Values with different letters within the same column are statistically different (P < 0.05; LSD); values ± standard deviation; TSS – total soluble solids; TA – titratable acidity (Maturity index)

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33% ETC. In addition, similar values were reported by Melo et al. (2006) for cv. Espada and Rosa mango fruits, the total proanthocyanidins amounted to 1.96 and 2.44 mg per 100 g, respectively. In short, these findings evidenced that the fruits from the water-stressed trees contained a higher TTS, ascorbate, and β-carotene, their contents are markedly differ-ent from the fruits under the non-water stressed trees. In this sense, the effect of the reduced irriga-tion represents a potential tool in producing natural antioxidants. Thus, this fact could be considered as a strategy for providing rich sources of antioxidant compounds for mango products (juice and pulp) that could favour its preservation without the need for synthetic antioxidants.

Sustainable intensification of subtropical farm-ing under environmental constraints. Agricultur-al land use expansions have dramatically increased the pressure on the availability of water. The increas-ing water shortage has caused the need to explore proper strategies for the sustainable use of irrigation water. That is, effective water-saving irrigation sys-tems, without causing a significant detrimental im-pact on the crop production, need to be adopted urgently, which will be one of the main goals in ag-ricultural sustainable intensification (Figure 5).

Habitually, the mango fruit is sold in Europe based primarily on the fruit size and, in some cultivars, the colour, both being the main commercial char-acteristics of the cv. Osteen that makes it the most cultivated and marketable fruit. Since the fruit weight is not a decisive aspect for quality in com-mercial terms, the medium-sized fruits are more appreciated by consumers. Therefore, the charac-terisation of this mango fruit grown in the sub-tropical region is essential in order for it to vie in the European market. Additionally, the fruit yields in SE Spain can be equated with the fully tropical zones, due to the high-density plantations in terraces (< 600 tree/ha) with an average fruit

yield from non-stressed (100% ETC) or from water-stressed trees (33% ETC) of 42.2 and 33.9 kg/tree, respectively. Moreover, the mango cultivation could provide environmental benefits and the fea-sibility of sustainable intensification of subtropi-cal farming by offering possibilities for fruit pro-duction with a lower amount of irrigation water, as has been demonstrated in the present experi-ment. Thus, a reasonable fruit yield, by boosting the sustainable water savings, has a crucial impor-tance as an adaptation and mitigation tool to meet water shortage situations. In addition, as was high-lighted in the present experiment, the fruit quality in terms of the physico-biochemical parameters were improved with the deficit irrigation and this fact is vital to establish an environmentally friendly market diversification—that is, to produce mango fruits with small or medium sizes containing high levels of various health-enhancing substances (i.e., TTS, carotenoids, vitamin C and dietary fi-bre). Therefore, rational water irrigation require-ments for the growth and development of mango tree could be ensured and an optimum water-use efficiency and improvements in the quality of the fruit could be achieved (Figure 5).

In this context, according to Martínez and Gómez (2016), consumers are willing to pay for singular foods, especially those cultivated and associated with environmentally friendly farming practices. In this line, Noguera et al. (2016) suggested an iden-tity brand to preserve this type of produced food as a hydroSOStainable product. For this, it will be crucial to establish a hydroSOStainable index in or-der to certify those products that have been pro-duced under sustainable-irrigation programmes. The consumer demand could be augmented, as would the price of the hydroSOS products and the profit for the farmers by convincing them about the economic benefits of deficit irrigation strate-gies. In this sense, Noguera et al. (2016) reported

Table 5. Impact of the irrigation on the carotenoid and anthocyanin contents for the cv. ‘Osteen’ mango fruit (± standard deviation)

Irrigation strategyViolaxanthin β-carotene Anteraxanthin Neoxanthin β-cryptoxanthin Methylcyani-

din-glycosideCyanidin-3- glycoside

Other anthocyanins

(µg/g pulp) (mg /100g peel)

100% ETC (Control) 1.97 ± 0.04 5.57 ± 0.76 1.28 ± 0.19 1.24 ± 0.06 2.04 ± 0.01 2.44 ± 0.21 1.22 ± 0.28 0.51 ± 0.04

75% ETC 1.89 ± 0.54 5.77 ± 0.83 1.28 ± 0.16 1.20 ± 0.01 2.04 ± 0.02 3.45 ± 1.24 2.35 ± 0.82 0.74 ± 0.19

50% ETC 1.24 ± 0.04 5.94 ± 0.87 1.12 ± 0.01 1.15 ± 0.02 2.02 ± 0.00 1.99 ± 0.70 1.29 ± 0.72 0.59 ± 0.06

33% ETC 3.05 ± 1.40 7.65 ± 1.22 1.52 ± 0.11 1.38 ± 0.15 2.09 ± 0.06 2.64 ± 1.07 1.68 ± 0.23 0.50 ± 0.19

9



that consumers were agreeable to pay a reasonably higher price for hydroSOS pistachios, if they are properly labelled and identified. Lipan et al. (2019) with almonds and Sánchez et al. (2019) with olives published studies with hydroSOS products. Howev-er, further research is needed to ascertain whether this willingness to pay could be similar for other fruits such as the mango.

CONCLUSION

The data found convey that taking advantage of the water stress will demand a better under-standing of the underlying mechanisms of the water shortage adaptation. That is, agricultural development is currently facing unprecedented challenges and it will be crucial in how to meet these challenges, in which the sustainable intensi-fication of agriculture plays a significant role, rely-ing on the integrated use of a wide range of strate-gies to manage the water, plant nutrients, pests and diseases. This work highlights the environmental, nutritional and economic benefits resulting from the application of deficit irrigation as a part of sus-tainable intensification practices in subtropical farming, for farmers as well as for consumers. Ad-ditionally, the mango fruits imported from over-seas are usually harvested unripe to finally reach the EU market, and are frequently lacking in taste,

scent and bioactive components that are highly ap-preciated by consumers. Distinctively, the Spanish mango fruit offers a quality, commercially ripe and consumption product in line with the market re-quirements by providing fruits completely ripened in their trees that could reach the European market within one or two days. Thus, the mango cultiva-tion in south-east Spain offers promising possibili-ties for supplying an environmentally friendly pro-duction and exporting high-quality fresh fruits.

REFERENCES

Abdel-Razik A.M. (2012): Effect of different irrigation re-gimes on quality and storability of mango fruits (Mangifera indica L.). Journal of Horticultural Science & Ornamental Plants, 4: 247–252.

Ali S.M., Bai K., Hanumantharaya B.G., Nagraj K.H. (2017): Micro-catchment techniques: an effective water conserva-tion practice in mango. International Journal of Current Microbiology and Applied Sciences, 6: 2965–2969.

AOAC (1984): Official Methods of Analysis. Association of Of-ficial Analytical Chemists. 14th Ed. Arlington, USA.

Bompard J.M. (2009): Taxonomy and systematics. In: Litz R. (ed.): The Mango: Botany, Production and Uses. CABI, Cambridge, USA: 19–41.

Chen J.P., Tai C.Y., Chen B.H. (2004): Improved liquid chro-matographic method for determination of carotenoids

Figure 5. Main influential factors and shift in the irrigation strategy to the sustainable intensification of subtropical farming in a Mediterranean environment

10



in Taiwanese mango (Mangifera indica L.). Journal of Chromatography A, 1054: 261–268.

Durán Z.V.H., Martínez R.A., Aguilar RJ., Franco T.D. (2003): El cultivo del mango (Mangifera indica L.) en la costa granadina. Grancopycenter, Granada, Spain.

Durán Z.V.H., Franco T.D. (2006): Rootstock influence on fruit yield, growth and mineral nutrition of mango (Man-gifera indica L. cv. Keitt). European Journal of Horticultural Science, 71: 102–108.

Durán Z.V.H., Rodríguez C.R., Francia J.R., Martín F.J. (2013): Land-use changes in s small watershed in the Mediter-ranean landscape (SE Spain): environmental implications of a shift towards subtropical crops. Journal of Land Use Science, 8: 47–58.

Elias F., Ruiz L. (1977): Agroclimatología de España. Cuad-erno I.N.I.A. No. 7, Madrid.

ESYRCE (2018): Encuesta sobre superficies y rendimientos de cultivos. MAPA, Pesca y Alimentación. Available at https://www.mapa.gob.es/es/estadistica/temas/estadis-ticas-agrarias/boletin2018_tcm30-504212.pdf (accessed May 10, 2019).

Fernández V.B., Rivadeneira M., Aguirre C. (2001): Cultivares de mango en el área subtropical de Salta y Jujuy. Revista de Información Sobre Investigación y Desarrollo Agropecu-ario, IDIA XXI 1: 113–117.

Ferreira B.P., Lima C.M.A., Elesbao A.R., Vieira F.R. (2018): Bioactive compounds and antioxidant activity in tropical fruits grown in the lower-middle São Francisco Valley. Revista Ciência Agronômica, 49: 616–623.

Galán S.V., Lu P. (2018): Achieving Sustainable Cultivation of Mangoes. Nº 34 de Burleigh Dodds Series in Agricultural Science. Cambridge. Burleigh Dodds Science Pub. Ltd.

García T.I.F., Durán Z.V.H. (2018): Water Scarcity and Sustainable Agriculture in Semiarid Environment: Tools, Strategies and Challenges for Woody Crops. 1st Ed., Neth-erlands. Academic Press Elsevier.

Gentile C., Di Gregorio E., Di Stefano V., Mannino G.., Per-rone A, Sortino G., Inglese P., Farina V. (2019): Food quality and nutraceutical value of nine cultivars of mango (Man-gifera indica L.) fruits grown in Mediterranean subtropical environment. Food Chemistry, 277: 471–479.

Godoy T.H., Rodriguez A.D.B. (1989): Carotenoid composi-tion of commercial mangoes from Brazil. Lebensmittel-Wissenschaft und Technologie, 22: 100–103.

Ibarra G.I.P., Ramos P.P.A., Hernández B.C, Jacobo V.D.A. (2015): Effects of postharvest ripening on the nutraceutical and physicochemical properties of mango (Mangifera indica L. cv. Keitt). Postharvest Biology and Technology, 103: 45–54.

Kader A.A. (2002): Quality and safety factors: Definition and evaluation for fresh horticultural crops. In: Kader AA (ed): Postharvest technology of horticultural crops. Pub-

lication 3311, 3rd Ed., Division of Agriculture and Natural Resources, University of California: 279–285.

Lawlor D.W., Cornic G. (2002): Photosynthesis carbon assimi-lation and associated metabolism in relation to water deficits in higher plants. Plants, Cell & Environment, 25: 275–294.

Lipan L., Cano L.M., Corell M., Sendra E., Hernández F., Stan L., Carbonell B.A.A. (2019): Sensory profile and ac-ceptability of HydroSOStainable almonds. Foods, 8: 64.

Madigu N.O., Mathooko F.M., Onyango C.A., Kahangi E.M., Owino W.O. (2009): Physiology and quality characteristics of mango (Mangifera indica L.) fruit grown under water deficit conditions. Acta Horticulturae (ISHS), 837: 299–304.

Martínez R.M.P., Gómez C.C.M. (2016): Key external in-fluences affecting consumer’s decision regarding food. Frontiers in Psychology, 7: 1618.

McGuire R.G. (1992): Reporting of objective color measure-ments. HortScience, 27: 1254–1255.

Melo E.A., Lima V.L.A.G., Maciel M.I.S., Caetano A.C.S., Leal F.L.L. (2006): Polyphenol ascorbic acid and total carotenoid contents in common fruits and vegetables. Brazilian Jour-nal of Food Technology, 9: 89–94.

Mercadante A.Z., Rodríguez A.D.B. (1998): Effects of ripen-ing, cultivar differences, and processing on the carotenoid composition of mango. Journal of Agricultural and Food Chemistry, 46: 128–130.

Mitra S., Mitra S.K. (2001): Studies on physico-chemical characteristics of 19 mango varieties grown in west Bengal. Indian Agriculturist, 45: 215–219.

Mukherjee S.K., Litz R.E. (2009): Introduction: botany and importance. In: Litz RE (ed.): Mango: botany production and uses. University of Florida, USA. Wallingford, CABI: 1–18.

Nagle M., Mahayothee B., Rungpichayapichet P., Janjai S., Muller J. (2010): Effect of irrigation on near-infrared (NIR) based prediction of mango maturity. Scientia Horticul-turae, 125: 771–774.

Noguera A.L., Lipan L., Vázquez A.L., Barber X., Pérez L.D., Carbonell B.A.A. (2016): Opinion of Spanish consumers on hydrosustainable pistachios. Journal of Food Science, 81: 2559–2565.

O’Neill E.M., Carroll Y., Olmedilla B., Granado F. (2001): A European carotenoid database to assess carotenoid intakes and its use in a five-country comparative study. British Journal of Nutrition, 85: 499–507.

Palafox C.H., Yahia E., Islas O.M.A., Gutiérrez, M.P., Ro-bles S.M., González A.G.A. (2012): Effect of ripeness stage of mango fruit (Mangifera indica L. cv. Ataulfo) on physiological parameters and antioxidant activity. Scientia Horticulturae, 135: 7–13.

Palaniswamy K.P., Muthukrishan C.R., Shanmugavclu K.G. (1975): Physicochemical characteristics of some varieties of mango. Indian Food Packer, 28: 12–19.

11



Rocha R.S.M., Queiroz J.H., Lopes R.Q.M.E., Campos F.M. (2007): Antioxidants in mango (Mangifera indica L.) pulp. Plant Foods for Human Nutrition, 62: 13–17.

Rodríguez P.C.R., Durán Z.V.H., Francia M.J.R., Muriel F.J.L., Franco T.D. (2011): Monitoring the pollution risk and water use in orchard terraces with mango and cherimoya trees by drainage lysimeters. Irrigation and Drainage Systems, 25: 61–79.

Salunkhe D.K. (1984): Mango. In: Salunkhe D.K., Desai B.B. (eds): Postharvest Biotechnology of Fruits, Boca Raton, Fla. USA. CRC Press: 77–94.

Sánchez R.L., Corell M., Hernández F., Sendra E., Moriana A., Carbonell B.A.A. (2019): Effect of Spanish-style processing on the quality attributes of HydroSOStainable green olives. Jour-nal of the Science of Food and Agriculture, 99: 1804–1811.

Spreer W., Nagle M., Neidhart S., Carle R., Ongprasert S., Muller J. (2007): Effect of regulated deficit irrigation and partial root zone drying on the quality of mango fruits (Mangifera indica L. cv. ‘Chok Anan’). Agricultural Water Management 88: 173–180. .

Tombesi A., Antognozzi E., Palliotti A. (1993): Influence of light exposure on characteristics and storage life of ki-wifruit. New Zealand Journal of Crop and Horticultural Science, 21: 87–92.

UC (2019): University of Canterbury, College of Science. Determination of vitamin C concentration by titration-redox titration using iodine solution. Christchurch, New Zealand. Available at https://www.canterbury.ac.nz/media/documents/science-outreach/vitaminc_iodine.pdf. (ac-cessed Dec 10, 2019).

Wei J., Liu G., Liu D., Chen Y. (2017): Influence of irrigation during the growth stage on yield and quality in mango (Mangifera indica L.). PLoS ONE, 12: e0174498.

Zanatta C.F., Cuevas E., Bobbio F.O., Winterhalter P., Mer-cadante A.Z. (2005): Determination of anthocyanins from camu–camu (Myrciaria dubia) by HPLC-PDA, HPLC-MS and NMR. Journal of Agricultural and Food Chemistry, 53: 9531–9535.

Received: March 20, 2020 Accepted: November 19, 2020

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Mango fruit quality improvements in response to water stress